1989 300e. would not start. did not hear the fuel pump energize. replaced fuel pump relay and it started and ran well for a week or so. then after reaching operating temperature, would stall and not restart until it had cooled down some. replaced the coolant temperature sensor at rear of block. ran well for again a week or so. then started the stalling and not restarting thing until water temperature fell from the 82 degree mark. then replaced the ovp relay as last resort. same condition. won't run after reaching the 82 degree mark. once the temperature drops to say 60 degrees, starts and runs fine. till i reach the 82 mark. anyone have any idea as what to try next? thank you. and happy new year to all.